A novel assay of biofilm antifungal activity reveals that amphotericin B and caspofungin lyse Candida albicans cells in biofilms
Article first published online: 15 JUN 2011
Copyright © 2011 John Wiley & Sons, Ltd.
Volume 28, Issue 8, pages 561–568, August 2011
How to Cite
DiDone, L., Oga, D. and Krysan, D. J. (2011), A novel assay of biofilm antifungal activity reveals that amphotericin B and caspofungin lyse Candida albicans cells in biofilms. Yeast, 28: 561–568. doi: 10.1002/yea.1860
- Issue published online: 1 AUG 2011
- Article first published online: 15 JUN 2011
- Accepted manuscript online: 16 MAY 2011 09:24PM EST
- Manuscript Accepted: 7 MAY 2011
- Manuscript Received: 27 JAN 2011
- National Institute of Allergy and Infectious Diseases. Grant Number: 1R01AI075033
- National Science Foundation. Grant Number: 0849892
- Candida albicans;
- amphotericin B
The ability of Candida albicans to form drug-resistant biofilms is an important factor in its contribution to human disease. Assays to identify and characterize molecules with activity against fungal biofilms are crucial for the development of drugs with improved anti-biofilm activity. Here we report the application of an adenylate kinase (AK)-based cytotoxicity assay of fungal cell lysis to the characterization of agents active against C. albicans biofilms. We have developed three protocols for the AK assay. The first measures AK activity in the supernatants of biofilms treated with antifungal drugs and can be performed in parallel with a standard 2,3-bis-(2-methoxy-4-nitro-5-sulphophenyl)-2H-tetrazolium-5-caboxanilide-based biofilm susceptibility assay; a second, more sensitive protocol measures the AK activity present within the biofilm matrix; and a third procedure allows the direct visualization of lytic activity toward biofilms formed on catheter material. Amphotericin B and caspofungin, the two most effective anti-biofilm drugs currently used to treat fungal infections, both directly lyse planktonic C. albicans cells in vitro, leading to the release of AK into the culture medium. These studies serve to validate the AK-based lysis assay as a useful addition to the methods for the characterization of antifungal agents active toward biofilms and provide insights into the mode of action of amphotericin B and caspofungin against C. albicans biofilms. Copyright © 2011 John Wiley & Sons, Ltd.